Department of Electrical Engineering, Pennsylvania State University, University Park, PA, USA.
Sci Rep. 2013;3:973. doi: 10.1038/srep00973.
The recent boom of energy storage and conversion devices, exploiting ionic liquids (ILs) to enhance the performance, requires an in-depth understanding of this new class of electrolytes in device operation conditions. One central question critical to device performance is how the mobile ions accumulate near charged electrodes. Here, we present the excess ion depth profiles of ILs in ionomer membrane actuators (Aquivion/1-butyl-2,3-dimethylimidazolium chloride (BMMI-Cl), 27 μm thick), characterized directly by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) at liquid nitrogen temperature. Experimental results reveal that for the IL studied, cations and anions are accumulated at both electrodes. The large difference in the total volume occupied by the excess ions between the two electrodes cause the observed large bending actuation of the actuator. Hence we demonstrate that ToF-SIMS experiment provides great insights on the physics nature of ionic devices.
最近储能和能量转换设备的蓬勃发展利用离子液体 (ILs) 来提高性能，这需要深入了解这种新型电解质在器件工作条件下的性能。对器件性能至关重要的一个核心问题是移动离子如何在带电电极附近积聚。在这里，我们通过飞行时间二次离子质谱 (ToF-SIMS) 在液氮温度下直接表征了离聚物膜致动器 (Aquivion/1-丁基-2,3-二甲基咪唑鎓氯化物 (BMMI-Cl)，27μm 厚) 中 IL 的过剩离子深度分布。实验结果表明，对于所研究的 IL，阳离子和阴离子都在两个电极上积累。两个电极之间过剩离子占据的总体积的巨大差异导致致动器观察到的大弯曲致动。因此，我们证明了 ToF-SIMS 实验为离子器件的物理性质提供了重要的见解。
